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New NASA Process Builds Parts One Layer at a Time

Friday, 30 October 2009

Engineers at NASA’s Langley Research Center in Hampton,
VA, have developed an environmentally friendly manufacturing
process called Electron Beam Freeform Fabrication
(EBF3). “You start with a drawing of the part you want to build,
you push a button, and out comes the part,” said Karen
Taminger, technology lead for the project. EBF3 works in a vacuum
chamber, where an electron beam is focused on a constantly
feeding source of metal, which is melted and then
applied as called for by a drawing — one layer at a time — on
top of a rotating surface until the part is complete.

To make EBF3 work, there are two key requirements: A
detailed 3D drawing of the object to be created must be available,
and the material the object is to be made from must be
compatible for use with an electron beam. First, the drawing is
needed to break up the object into layers, with each cross-section
used to guide the electron beam and source of metal in
reproducing the object, building it up layer by layer. Second,
the material must be compatible with the electron beam so
that it can be heated by the stream of energy and briefly turned
into liquid form, making aluminum an ideal material.

The EBF3 can handle two different sources of metal at the
same time, either by mixing them together into a unique alloy
or embedding one material inside another. The potential use
for the latter could include embedding a strand of fiber optic
glass inside an aluminum part, enabling the placement of sensors
in areas that were impossible before.
Future lunar base crews could use EBF3 to manufacture
spare parts as needed, rather than rely on a supply of parts
launched from Earth. But the immediate and greatest potential
for the process is in the aviation industry, where major
structural segments of an airliner, or casings for a jet engine,
could be manufactured for about $1,000 per pound less than
conventional means.

Environmental savings also are made possible by deploying
EBF3. Normally, an aircraft builder might start with a 6,000-
pound block of titanium and machine it down to a 300-pound
part, leaving 5,700 pounds of material that needs to be recycled
and using several thousand gallons of cutting fluid used in
the process. With EBF3, the same part can be built using only
350 pounds of titanium and machine away just 50 pounds to
get the part into its final configuration.

For more information, visit www.nasa.gov/topics/aeronautics/features/electron_beam.html.

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